Hi,
I have an application with 4 different opengl context. On each I render a quite big mesh (between 800k~1000k facets with400k~700k vertex) I put each object in a VBO and render them with
glDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, vboIndices);

When I breakpoint the rendering method, I notice that the 3 first objects execute correctly the glDrawElement, but the fourth just freezes...No opengl error occured...
I tried on a GeForce 7600GS with same data, everything works fine but not on my Radeon X1300
My drivers are up to date.
Is it a memory issue? (256MB on ATI) How can I know the remaining amount of video memory?
is it an ATI limitation?

macarter

01-16-2008, 07:18 AM

Try Catalyst 7.11 driver. I believe that 7.12 introduced the rewritten driver to many older cards along with a batch of new bugs.

alfalf3

01-16-2008, 07:27 AM

Thanks for the advice, I'll check that.
I forgot to say that I have succeeded in rendering smaller objects.
Seems to be a memory problem or a limitation of the number of polygon indices handled by the card??
Do you know how can I check dynamiccally the remaining memory available on the graphic card?

Luhtor

01-16-2008, 11:02 AM

The X1300 is not a powerfull graphic card :)

400k~700k vertices are quite a lot for it. What are your fragment operations ?
If you're only using a simple color, you should have at least 100fps on a X1300.

alfalf3

01-17-2008, 12:34 AM

It works correctly with 7.11 drivers!!!???
I have to test my VBO implementation on different video cards, do I have to test also with different driver version???
That's just crazy... :sick:

At the beginning, I changed my initial implementation from display lists to VBO because I experienced important performance difference between NVidia and ATI(NVidia was much more efficient) and I though VBO would make performance more homogeneous...

The problem is: when developing a large public application, you need to ensure it is fully usable on a large video card panel.

Korval

01-17-2008, 01:21 AM

I have to test my VBO implementation on different video cards, do I have to test also with different driver version???

As Macarter mentioned, 7.12 contains a totally rewritten GL implementation. Naturally, it will have different bugs from the 7.11 driver. Just like if you write some new code to replace a system, it will have different bugs from the system you replaced.